Sewing machine needle

Abstract

A sewing machine needle capable of preventing stitch skipping and fabric yarn breakage, irrespective of high-speed and multifunction sewing machines and diversified materials being used. Over a predetermined length from an edge, closer to a needle point, of a needle eye toward the needle point, a blade has a straight profile extending parallel to a longitudinal axis of the needle as viewed from a side of the needle in a direction orthogonal to a direction in which the needle eye extends. Over a predetermined length from the straight profile portion toward the needle point, the profile of the blade is a flat cross-section in which the thickness thereof in the direction in which the needle eye extends is larger than the width thereof in the direction orthogonal to the direction in which the needle eye extends. In a needle point portion following the flat cross-section portion and extending to the needle point, the blade has a sectional shape of a perfect circle.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a sewing machine needle having less possibility of causing stitch skipping or fabric yarn breakage, irrespective of high-speed and multifunction sewing machines and diversified materials being used.[0003]2. Description of the Related Art[0004]Sewing machines used in sewing are roughly classified into ones for industrial use and ones for domestic use.[0005]The industrial sewing machines are generally used at high rotational speeds from the viewpoint of pursuing productivity, and the rotational speed thereof may come up to as high as 8000 rpm. In automated industrial sewing machines, seams are formed in multi-directions and loops that are important for formation of the seams tend to become unstable under the influence of sewing threads having a certain twist angle.[0006]A fabric feeding mechanism of automated sewing machines such as pattern seamers or cycle sewing machines employs an X-Y t...

AI Technical Summary

Benefits of technology

[0011]The present invention has been made in order to solve the above problems. It is therefore an object of the present invention to provide a sewing machine needle capable of preventing stitch skipping and fabric yarn breakage, irrespective of high-speed and multifunction sewing machines and diversified materials being used.

[0013]In the case of the sewing machine needle thus configured, by virtue of such a configuration that over a predetermined length from the edge, closer to the needle point, of the needle eye toward the needle point, the blade has the straight profile extending parallel to the longitudinal axis of the needle as viewed from the side of the needle in the direction orthogonal to the direction in which the needle eye extends, it is possible to reduce the clearance between the blade of the needle and a needle dropping portion of a rotary hook during sewing, to thereby more positively suppress the occurrence of stitch skipping as compared with conventional sewing machine needles.

[0014]By virtue of such a configuration that over a predetermined length from the straight profile portion toward the needle point, the blade has the profile of a flat cross-section in which the thickness thereof in the direction in which the needle eye extends is larger than the width thereof in the direction orthogonal to the direction in which the needle eye extends, it is possible to lower a puncture resistance of the sewing machine needle, to thereby suppress the occurrence of fabric yarn breakage during sewing.

[0015]By virtue of such a configuration that in the needle point portion following the flat cross-section portion and extending to the needle point, the blade has the sectional shape of a perfect circle, the needle point portion is allowed to slide on the surfaces of fabric yarns to penetrate fabric when the needle point portion is inserted into the fabric, whereby it is possible to prevent the needle point portion from damaging the fabric yarns, and it is possible to uniformly distribute in all directions the resistance to which the fabric yarns in contact with the perfect circle section of the needle point portion are subjected and reduce the resistance, to thereby more positively prevent the occurrence of the fabric yarn breakage.

Problems solved by technology

In automated industrial sewing machines, seams are formed in multi-directions and loops that are important for formation of the seams tend to become unstable under the influence of sewing threads having a certain twist angle.

When a tip of a rotary hook passes a scarf of a sewing machine needle, minute oscillations of the X-Y table cause a large shaking of the needle from the scarf thereof to a needle point thereof.

As a result, the tip of the rotary hook fails to catch a loop so that stitch skipping is liable to occur.

Due to a tip end portion of the sewing machine needle having to reciprocate through the needle dropping hole, however, the dimensions of the needle dropping hole can not be made smaller than the thickness of the needle in a direction in which a needle eye extends.

In addition, since the tip end portion of the conventional sewing machine needle is tapered, the clearance between the needle and the needle dropping hole inevitably becomes large.

Since their mechanisms are similar to those of the automated industrial sewing machines, the household sewing machines are also facing the same problems as those of the industrial sewing machines.

Extremely delicate jersey-based materials have also come to be used for automobile seats and have posed another essential problem of fabric yarn breakage in addition to the sewing problems such as stitch skipping and needle breakage.

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